Energy-saving Solar Panel

ABSTRACT

Disclosed is an energy-saving hollow sheet whose spacing bars between the multiple panels are totally canceled; whose positions of screw hole have cylinders of certain thickness mounted by directly moulding, gluing, assembling, etc.; whose panels have frame at their brim; whose panels&#39; distances and positions to each other are fixed by the above cylinders and frames with the distances between the panels controllable and the number of panel layers addable thereby, resulting in a thermal insulating performance able to reach any level; whose cancel of the spacing bars can bring a transparency same to glass curtain walls.

FIELD OF TECHNIQUE

This energy-saving hollow sheet pertains to the construction industry.

BACKGROUND TECHNIQUES

1) Hollow sheets are multiple-layer panels made of high polymermaterials (polycarbonate, polyester resin, polymethyl metharcrylate,polypropylene plastics, etc). Since it was created in the 70s of the20th century, thanks to its light weight, high strength, and many otherproperties in terms of thermal insulation, sound insulation, etc., itsapplication has become more and more wide, with an ever-increasingoutput. Nowadays, its price has fallen to more than 10 CNY per squaremeter, and more than 20 CNY per kilogram. With such low price, as longas its structure and installation methods can be further improved, thenits thermal insulation can be raised to the same level as an insulatedbrick wall (in the past its thermal insulation was just equal to that ofa glass curtain wall), its installation and replacement can beconveniently done, and it can achieve the same full transparency as aglass curtain wall. When the requirements in these three aspects aremet, then it can completely substitute curtain walls and roofs duringconstruction of houses, greatly lowering the cost of construction andimproving the building's energy-saving to any needed level.

2) In the technology of a publicized patent (CN105507432A), a structureof glass curtain wall with any number of layers and cavities isdescribed, which glass can be replaced by other plastic materialsproduced through directly moulding, welding, etc., bringing any neededthermal insulation performance. The installation of its curtain wall andskylight can be directly carried out inside the room, sparing thetraditional scaffold. If the above technology is to be combined with thehollow sheets, as long as the corresponding adjustments and developmentsare made, the above three requirements can be met. See the details ofthese adjustments and developments as below.

TECHNICAL SOLUTIONS

1) Structure of Energy-saving Hollow Sheet

A) In a traditional hollow sheet, two or more layers of panel areconnected one above another with spacing bars in between, which spacingbars form the sectional shape of square, layers of square, beehive, etc.Cavities are formed between the layers of panel, improving the functionsof thermal insulation, sound insulation, and boosting its strength.However, up to now the thermal insulation performance of the varioushollow sheets can only reach the level of glass curtain wall, not ableto rise up to that of thick brick walls, much less that of insulatedbrick wall. To attain wide application of the hollow sheet at buildings'external wall, this problem of thermal insulation must be solved.Probing into the reasons, it might be noticed that thickness of thegrid-shaped spacing bars between the panel of a hollow sheet is around 1millimeter, which is hundreds times thicker than that of the bubbledplastic's wall, or the insulating cotton's fiber. Thence, during theprocess of thermal conduction, the heat would not be timely transferredto the air surrounding the hollow sheets' spacing bar like that with thebubbled plastic's wall or the insulating cotton's fiber, forming athermal bridge with the hollow sheet. If thickness of the hollow sheet'sspacing bars is greatly reduced, then it would become too soft tosupport the multiple layers of panel and keep their relative positions.To solve this problem, the structure in FIGS. 1,2 can be applied:Between panels 1,2,3,4 the spacing bars are totally or mostly cancelled(see the side view in FIG. 1); At the position of bolt hole 5, cylinders6,7,8 are set, which cylinders can be produced by directly moulding orwelding, etc. and shall have a certain thickness (Surrounding thesecylinders insulating rings shall be set); At the four sides of panel1,2,3,4 shall be set side frame 9 (see the top view in FIG. 2 and theside view in FIG. 1); The distances between and relative positions ofpanels 1,2,3,4 are totally or mainly fixed by cylinders 6,7,8 and sideframe 9; During installation, the bolt can pass through cylinders 6,7,8.By this way, the problem of heat conductivity between the multiplepanels can be solved, greatly improving its thermal insulatingperformance. At the same time, the number of the panels' layers can beincreased at will, so can the distances between the layers be adjusted(At this time the screws need to be replaced by bolts), so that therenovated hollow sheet can reach any level of thermal insulation. Inaddition, when all the spacing bars are cancelled, the obstacles tosight would be eliminated at the same time, resulting in the samefunction of transparency as glass curtain wall.

B) As the above energy-saving hollow sheet has cancelled the spacingbars between the panels, its strength would be decreased to an extent.At places where it needs to be stronger, thickness of its outer layersof panel can be increased; If its function of transparency does not needto be kept, the structure in FIG. 3 can also be applied: Hollow sheet1's cavities 2,3 keep the traditional spacing bars; Cavities 4,5,6 applythe insulating structure described above; At the two sides 7,8 ofcavities 4,5,6 the spacing bars are also kept. Depending on the specificrequirements on strength and insulation, the number of structuralcavities 2,3 etc. and that of the insulating cavities 4,5,6 etc. can beadjusted accordingly. If the width of cavities 4,5,6 is not great,cylinder 9 can be canceled, and the bolt hole cannot be set at positionof these cavities. The bigger width of cavities 4,5,6, the betterthermal insulation. Vice versa.

2) Installation of Energy-saving Hollow Sheet

According to different requirements on thermal insulation, thickness ofthe above energy-saving hollow sheet can vary in a fairly big range (Forthe specific way to determine its thickness, paragraph 0114 of PatentCN105507432A may be referenced: On the basis of different climates andthe building's aimed insulating level or heat transmission coefficient,the structure and thickness of materials at every part of the buildingshall be determined. For the hollow sheet, preliminary calculation onthe overall thickness of its cavities and heat conductivity of the airnot in a state of convection shall be done, with specific experimentsmade, so that it can be assured that the heat transmission coefficientsof every part of the building match each other, avoiding bottle necks.At the same time, the heating conditions at different parts of thebuilding shall be examined, with adjustments done accordingly. e.g. Atthe roof under the hot sun, the thermal insulating requirement shall behigher than that of the external wall; At position of a stove inside theroom, the thermal requirement is also higher than elsewhere). If itsinsulation level needs to be raised to that of an insulated brick wall,its thickness would be several times greater than the traditional hollowsheet (but its weight could be roughly kept unchanged). Under thesecircumstances, the screws used for installation of traditional hollowsheet would not work, bolt and bolt nut, etc. would need to be used.What's more, due to the limited service time of hollow sheet (usually itcannot surpass 20 years), it needs to be replaced in time according toits specific service time. For convenience of its installation andreplacement, easier and faster installation methods need to bedeveloped. See details in the later part “Concrete ImplementationMethods”.

3) Door and Window

When using the energy-saving hollow sheet, it's needed to useenergy-saving door and window whose thermal insulation performance matchthe hollow sheet. In the patent mentioned above, the door and windowwith any layer of cavities addable can meet this requirement. Whenmanufacturing this type of door and window using materials of polycarbonate etc., according to the specific requirements on structuralstrength, function of transparency, and insulating level, the structuresin FIG. 1 or 3 in the previous text can be applied (For convenience, inthe following text they are called “structure A” and “structure B”respectively). For door and window with anti-burglary requirement, steelnet, metal grid, etc. can be installed on the door and window's rigidframe.

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1,2 are Hollow Sheet With Insulating Structure;

FIG. 3 is Hollow Sheet With Combination of Insulating Structure andSpacing Bar Structure;

FIG. 4 is Rain-proofing Connection of Upper and Lower Hollow Sheets;

FIG. 5 is Rain-proofing Connection of Left and Right Hollow Sheets;

FIG. 6 is Rain-proofing of Bolt Hole For Outdoor Installation;

FIG. 7 is Rain-proofing of Bolt Hole For Indoor Installation;

FIG. 8 is Connecting Rod Outside Floor;

FIG. 9 is Rain-proofing of Insulating Block;

FIGS. 10,1 1 are Adjustment of Insulating Block at Position ofConnecting Rod;

FIGS. 12, 13 are Combination of Vertical Rain Cover and HorizontalInsulating Block;

FIG. 14 is Installation of Rain Cover on Vertical Frame ofmultiple-storey buildings.

CONCRETE IMPLEMENTATION METHODS

1) Outdoor Installation:

A) When the frames of a house, stadium, conservatory, etc. have beenconstructed, structure A and structure B described in the previous textcan be installed onto the frames. According to the thermal expansioncoefficient of the hollow sheet's material, the diameter of bolt hole 5in FIG. 1 needs to be bigger than the diameter of bolt and has enoughspace for the hollow sheet's displacement caused by thermal expansion.At the same time, the bolt nut needs to have a gasket or blocking platewith a dimension bigger than the bolt hole (otherwise the bolt would notbe able to fix the hollow sheet). Also, between two neighboring hollowsheets there shall be set a space enough for their expansion. In theserespects there are already a lot of experiences and techniques forreference. The difference here is that the energy-saving hollow sheetmay be much thicker than the traditional one, so bolts of correspondinglengths need to be fixed to the building's frame through bolt nuts,welding, etc.

B) For convenience of the hollow sheet's installation and replacement,when it is installed outdoors, its rain-proofing can be done as follows:

a) When the hollow sheet is installed vertically or obliquely (usuallyas a wall it is installed vertically; as a roof it is installedobliquely), at where the upper and lower hollow sheets connect, thesection in FIG. 4 can be applied: At the lower brim of upper hollowsheet 1 there is set a covering plate 2. If covering plate 2 needs to bemade stronger, ribs 3 can be set on it at intervals. Covering plate 2can cover the upper brim of lower hollow sheet 4, so that the raincannot enter the space between hollow sheet 1 and 4. The bigger width ofcovering plate 2, the better function of rain-proofing. Duringinstallation, lower hollow sheet 4 needs to be installed before upperhollow sheet 1. When the above covering plate is applied on the roof,the roof cannot be set level, but should have a slope (Angle of thisslope shall be determined according to the maximum rainfall of thearea).

b) The connection of left and right hollow sheets can be done as in thetop view of FIG. 5: Rain cover 1 is fixed by bolt 2 to the building'sframe (For rain-proofing of the bolt hole in the rain cover, see sectionc in the following text); Hollow sheets 3,4 have rain-proofing plate 5,6respectively; Between hollow sheets 3,4 there is enough space forexpansion; When the hollow sheets expand or shrink, rain-proofing plates5,6 can move within the space under rain cover 1; Rain cover 1 andrain-proofing plates 5,6 can prevent the rain from entering the spacebetween hollow sheets 3,4. The shape of rain cover 1 has someresemblance to the U-shaped locker of current techniques. The differenceis that the U-shaped locker can be locked onto the curved edge of twoneighboring hollow sheets while the hollow sheets at the two sides ofrain cover 1 have no curved edge and the rain cover cannot be locked.Furthermore, the hollow sheets can freely move under the rain cover, andinside the rain cover there needs to be set an insulating layer to reachthe same insulating level as the hollow sheets.

During installation, the upper rain cover shall be aligned with thelower rain cover, and at the lower brim of the upper rain cover thereshall be set a covering plate, which covering plate shall cover theupper brim of the lower rain cover, in a similar way to the connectionof upper and lower hollow sheets. If under special circumstances theupper and lower rain covers cannot be aligned, then at the upper end ofthe rain cover there needs to be set a slant plate, which slant plateneeds to be connected to under the covering plate of the hollow sheetabove it; At the same time, at the lower end of the rain cover thereneeds to be set a covering plate to cover the upper brim of the hollowsheet under it.

c) Rain-proofing of the bolt hole can be done as in FIG. 6: Bolt 1 isfixed to the building's frame; Rain-proofing ring 2 (which can be madewith the same material as the hollow sheet) is fixed by welding orgluing on hollow sheet 3 (or on a rain cover) around bolt hole 4; Thediameter of rain-proofing ring 2′s bottom is smaller than its top sothat the rain running on hollow sheet 3 cannot enter the rain-proofingring; Near the top of bolt 1 there is set stopping panel 7 which isfixed by bolt nuts 5,6; Stopping panel 7 and the supports under hollowsheet 3 can prevent hollow sheet 3 from vertically moving, but allow itto move horizontally (Inside rain-proofing ring 2 there is space, sobolt 1 is not wrapped by rain-proofing ring 2. Therefore, althoughhollow sheet 3 is connected to rain-proofing ring 2 to form one body,hollow sheet 3 can still move in the front-back and left-rightdirections); Stopping panel 7 needs to cover rain-proofing ring 2, andon bolt nut 6 there must be installed insulating cover 8 andrain-proofing cap 9 (They may be fixed by glue if necessary);Rain-proofing cap 9 can prevent the rain from entering the bolt hole atthe middle of stopping panel 7; Stopping panel 7 can prevent the rainfrom entering rain-proofing ring 2; Thus the rain would not be able toenter the bolt hole in hollow sheet 3.

C) With structure A described in the previous text (see FIG. 1), thecavities are closed. When the ambient temperature changes, thedifference of air pressure can make the hollow sheet convex or concave.If the cavities are opened to the outside, then the vapor may mist thecavities, affecting its function of transparency. To solve this problem,the cavities can be connected to air-bags: When the cavities are heated,the expanded air would be discharged into the air-bags; When thecavities are cooled, the air in the air-bags would be sucked into theair-bags. If the cavities are filled with inert gas, its thermalinsulating function can be further improved. With structure B describedin the previous text (see FIG. 3), the cavities can be set ashalf-closed: When there is a difference of air pressure, the air canmove into or out of the cavities through small holes or filteringpanels; When there is no difference of air pressure, the air would notmove into or out of the cavities.

D) For highly energy-saving buildings, if the energy-saving hollowsheets are installed outdoors, the frame of building should be totallycovered by the hollow sheets, avoiding as much as possible that any partbe uncovered. Also, the bolt nuts on the hollow sheets and the part ofbolts protruding above the hollow sheets shall be securely covered byinsulating caps or sheaths, with structural adhesive used if necessary.Adjacent hollow sheets must be sealed: Between the hollow sheets and theframe of building there shall be installed gasket of neoprene etc., sothat the hollow sheets can move but keep being sealed. At the inner sideof the outermost panel in the hollow sheet there shall be added aanti-thermal-radiation and anti-ultraviolet coating (This coating canalso be added at other layers of panel. But it shall be avoided to makethe coating on the hollow sheet's surface, so as to avoid that thecoating be scared or fall off). The hollow sheet's fire rating andcontent of hazardous substances, etc. must also meet the relatedstandards.

2) Indoor Installation:

A) Single-storey Building

When installing the hollow sheets indoors for a single-storey building,the methods are similar to that of outdoor installation described above.The differences are:

a) When the hollow sheets are installed as the roof, they are hung underthe frame of the roof with the bolts pointing downward. Rain-proofingneeds to be done near the root of the bolts to prevent that the rainflow along the bolt into the room. When the hollow sheets are installedas the external wall, the bolts point inward, and rain-proofing alsoneeds to be done near their root. The rain-proofing can be done as inFIG. 7: Near the root of bolt 1 is set a spherical surface 2; The top ofstopping panel 3 is set as a convex; At the root of this convex there isa rain groove 4. Push Stopping panel 3 to spherical surface 2 and usebolt nut 5 to make it fixed. At the same time, on hollow sheet 6 setrain-proofing ring 8 around bolt hole 7 (in the same way as in FIG. 6).Then push hollow sheet 6 upward to let bolt 1 enter bolt hole 7. Nextadd gasket and bolt nut at the lower end (or the inner end) of bolt 1,so that hollow sheet 6 would be fixed under the frame of roof (or insidethe frame of external wall), and the rain would be prevented fromentering bolt hole 7. At the lower end or inner end of bolt 1 thereshall be installed a insulating cap.

b) When the hollow sheets are installed as the external wall, everyupper row of hollow sheets shall be installed before the lower row.Otherwise, the lower row would block the covering plate of the upper row(see FIG. 4) .

c) When the rain cover (see FIG. 5) is installed between the neighboringleft and right hollow sheets, the rain cover shall be installed first(at this time the direction that the bolt points in is opposite to thatin FIG. 5, and is the same as the direction of the bolt in FIG. 7). Thenthe hollow sheets at the two sides shall be installed (This order ofinstallation is the inverse of that with outdoor installation).

d) With single-storey buildings, when the hollow sheets are installedindoors, they do not need to cover the frame of building, so differentvisual effects can be created, yet their thermal insulating performancewon't be second to that of outdoor installation.

B) Multiple-storey Building

For multiple-storey buildings, indoor installation is more significant,because replacement of the hollow sheets, which have a relative shortservice life, is much more easily and safely carried out indoors thanoutdoors on the higher floors of the building. For indoor installationand replacement of hollow sheets on multiple-storey buildings, on thebasis of the methods with single-storey as described above, thefollowing adjustments need to be made:

a) Based on the patent mentioned in the previous text, in FIG. 8,outside a multiple-storey building's floor there shall be installedconnecting rods 1,2 (Due to the light weight of hollow sheet, theseconnecting rods do not need to be directly pre-embedded in the concreteframe of building, but can be fixed onto relatively sparse pre-embeddedbolts etc.). Connecting rods 1,2 are respectively inserted in the boltholes of upper hollow sheet 3 and lower hollow sheet 4; Theirrain-proofing can be done as per what's described above (see IndoorInstallation Aa). The curved shape of the connecting rods can furtherprevent the rain from entering the room.

b) Based on the patent mentioned in the previous text, in FIG. 9,outside a multiple-storey building's floor there shall be installedinsulating block 1; At the top and bottom of insulating block 1's innerside there shall be respectively set rain-proofing plates 2, and acovering plate 3. At the same time, on upper hollow sheet 4 there shallbe set covering plate 5 through gluing, welding, etc.; Covering plate 5shall be set at the same height as the top of rain-proofing plate 2 andits lower brim shall be elastic and lower than the top of rain-proofingplate 2. During installation, insulating block 1 shall be installedfirst; Then install the upper and lower hollow sheets. When installingthe upper hollow sheet, its bolt hole shall be put onto the connectingrod (see description in the previous paragraph), then it shall be pushedoutward till the lower brim of covering plate 5 is pushed against thetop of rain-proofing plate 2 and is bent. Then continue with the outwardpushing till covering plate 5 surpasses rain-proofing plate 2 and itslower brim restores the original shape, so that the rain would not beable to flow into the space between the hollow sheet and the insulatingblock. When the hollow sheet has been pushed to the limit, installgasket, bolt nut, and insulating cap at the end of the bolt. The biggerwidth of covering plate 5 and its lower brim, the better function ofrain-proofing. But the rigid part of covering plate 5 needs to be set ata position a little higher than the top of rain-proofing plate 2;Otherwise covering plate 5 might not be able to surpass rain-proofingplate 2 smoothly or might cause damage. At the same time, the bottom ofcovering plate 5's rigid part shall be set slanting outward, so shallthe top of insulating block 1's top be set. In this way, their functionof rain-proofing can be further improved. When removing the hollowsheet, the insulating cap, bolt nut, and gasket shall be removed first;Then pull the hollow sheet inward (On the inner side of the hollow sheetthere shall be set handles for the pulling).

At position of the connecting rods described above (at part a), theinsulating block described in the previous paragraph needs to be madewider and thicker (If the connecting rods are horizontally close to eachother, the whole insulating block may be made wider and thicker) withspace set at its inner side, so that the connecting rods can be covered(see the front view in FIG. 10: Insulating block 1 needs to be madewider and thicker at the connecting rods' positions 1 a, 1 b). At thesame time, the insulating block's rain-proofing plate 2 and the coveringplate of the hollow sheet above it shall be set along its side line 3(see the front view in FIG. 10). At position of the side line's verticalpart 3 a, there shall be set on rain-proofing plate 2 a brim 3 bpointing outward (see the enlarged top view in FIG. 11), so that therain would be prevented from flowing to the inside.

At where the horizontal insulating block and the vertical rain covermeet (see Outdoor Installation Bb and FIG. 5), vertical rain cover 1 canbend outward (see the side view in FIG. 12 and the front view in FIG.13), so that it can cover insulating blocks 2,3 at its two sides.

c) The rain cover described in the previous text (see OutdoorInstallation Bb and FIG. 5) needs to be installed at the outside of thebuilding's vertical frame (Because the vertical frame has only a limitedwidth, the installation can still be done indoors. See the top view inFIG. 14, wherein rain cover 2 is installed outside frame 1). On a samefloor, installation of the rain cover need to be done prior to that ofthe hollow sheet. And, as in FIG. 14, according to the width of thebuilding's vertical frame 1, rain cover 2 needs to have adjustmentsaccordingly, so that it can surpass frame 1 at the two sides and hollowsheets 3, 4's rain-proofing plates 5, 6 can move in the space at theinner side of rain cover 2.

d) On the top floor of a multiple-storey building, installation andreplacement of the hollow sheets for the roof can be directly doneindoors.

e) Based on the technology of the patent mentioned in the previous text,at the edge of the floor of and above the second storey there must beinstalled safety railing or safety net (If the hollow sheet has a panelstrong enough and is installed securely enough, then the safety railingor net may be canceled). At positions with Anti-burglary requirement,there shall be installed anti-burglary net. On every hollow sheet,insulating block, rain cover, etc. there must be moulded the time ofproduction, and they must be replaced in time.

f) This energy-saving hollow sheet can also be used as partition wallinside the building. With the cancel of spacing bars, itssound-insulating function can improved.

3) Application of Energy-saving Hollow Sheet

The energy-saving hollow sheet used on multiple-storey buildings has aweight times lower than glass curtain wall, yet has higher strength andlower risk of breakage or falling off. Therefore, it can significantlyincrease the overall height of a building, and can be widely applied onresidential buildings, office buildings, hotels, etc., resulting inhigher efficiency of land use and further-decreased price of housing.

When the energy-saving hollow sheet is applied on houses with frame ofreinforced concrete, as the bearing wall is canceled, to ensure thehouse's anti-seismic function, the horizontal beam's span must not beset too long, and shear walls or counter-shear structures shall be set.If steel structure is selected for the house's frame, its anti-seismicfunction can be improved. With whatever type of structural frame, anordinary high-rise building must not be designed to look like a pen.Otherwise its foundation would not suffice to resist the horizontal wavein a earthquake. Only when the ratio of the building's area offoundation to its height is made large enough, and proportion of thebuilding's length and width are suitable, avoiding narrow and straighttypes whose shape in top view is like the longitudinal section of astick, and applying the types with shape of a square, a cross, etc. intop view—can the building's anti-seismic function be assured.

When the energy-saving hollow sheet is applied on various types ofbuilding, any level of thermal insulation can be achieved, and theproblem of energy-saving can be fundamentally solved, resulting in thecomprehensive benefits in the long run.

1. An energy-saving hollow sheet whose spacing bars between the multiplepanels are totally canceled; whose positions of screw hole havecylinders of certain thickness mounted by directly moulding, gluing,assembling, etc.; whose panels have frame at their brim; whose panels'distances and positions to each other are fixed by the above cylindersand frames with the distances between the panels controllable and thenumber of panel layers addable thereby, resulting in a thermalinsulating performance able to reach any level; whose cancel of thespacing bars can bring a transparency same to glass curtain walls. 2.The energy-saving hollow sheet according to claim 1, wherein the spacingbars and the insulating structures are combined: at the outer layers thecavities have spacing bars so as to keep the structural strength; at theinner layers the cavities have no spacing bar so as to bring theinsulating function; the numbers of outer layers for structural strengthand that of the inner layers for insulation function can be adjustedaccording to the specific requirements on strength and insulation. 3.The energy-saving hollow sheet according to claim 1, wherein a raincover is set between two hollow sheets in left-and-right connection: therain cover is fixed to the building's frame with sufficient space at theinner side of rain cover for expansion of the hollow sheets; at the edgeof the hollow sheets there are set rain-proofing plates to prevent therain from entering the space between the hollow sheets; at the lowerbrim of the upper rain cover there is set a covering plate to cover theupper brim of the lower rain cover.
 4. The energy-saving hollow sheetaccording to claim 1, wherein the bolt hole has a rain-proofing ring:the diameter at the bottom of the rain-proofing ring is smaller than atits top, so as to prevent the rain from surpassing the rain-proofingring.
 5. The energy-saving hollow sheet according to claim 1, which canbe used in a multiple-storey building: the floors of the building haveinsulating blocks with a rain-proofing plate and a covering platerespectively set at the top and bottom of the insulating block; at thesame time, the hollow sheet above the floor has a covering plate setnear its lower side, which covering plate has an elastic lower brim witha height lower than the top of the rain-proofing plate on the insulatingblock; during installation of the hollow sheet, when it is being pushedoutward, the lower brim of its covering plate surpasses the top of therain-proofing plate on the insulating block and then restores itsoriginal shape, so as to prevent the rain from entering the spacebetween the hollow sheet and the insulating block; also, the bottom ofthe rigid part of the hollow sheet's covering plate is set slantingoutward, so is the top of the insulating block set, thus furtherimproving their rain-proofing fun